Financing Receivables (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Commercial mortgage loans
Gross commercial mortgage loans	$ 4,302	$ 4,368
Less: allowance for loan losses	55	60	62	64
Commercial Mortgage Loans
Commercial mortgage loans
Percent of commercial mortgage loans with highest risk rating	2.00%	3.00%
Gross commercial mortgage loans	2,584	2,624
Less: allowance for loan losses	33	35
Net commercial mortgage loans	2,551	2,589
Percentage of gross commercial mortgage loans	100.00%	100.00%
Commercial Mortgage Loans | Apartments
Commercial mortgage loans
Gross commercial mortgage loans	410	392
Percentage of gross commercial mortgage loans	16.00%	15.00%
Commercial Mortgage Loans | Hotel
Commercial mortgage loans
Gross commercial mortgage loans	50	51
Percentage of gross commercial mortgage loans	2.00%	2.00%
Commercial Mortgage Loans | Industrial
Commercial mortgage loans
Gross commercial mortgage loans	483	480
Percentage of gross commercial mortgage loans	19.00%	18.00%
Commercial Mortgage Loans | Mixed Use
Commercial mortgage loans
Gross commercial mortgage loans	42	42
Percentage of gross commercial mortgage loans	1.00%	2.00%
Commercial Mortgage Loans | Office
Commercial mortgage loans
Gross commercial mortgage loans	640	694
Percentage of gross commercial mortgage loans	25.00%	26.00%
Commercial Mortgage Loans | Retail
Commercial mortgage loans
Gross commercial mortgage loans	830	845
Percentage of gross commercial mortgage loans	32.00%	32.00%
Commercial Mortgage Loans | Other
Commercial mortgage loans
Gross commercial mortgage loans	129	120
Percentage of gross commercial mortgage loans	5.00%	5.00%
Commercial Mortgage Loans | East North Central
Commercial mortgage loans
Gross commercial mortgage loans	253	252
Percentage of gross commercial mortgage loans	10.00%	10.00%
Commercial Mortgage Loans | East South Central
Commercial mortgage loans
Gross commercial mortgage loans	64	65
Percentage of gross commercial mortgage loans	2.00%	2.00%
Commercial Mortgage Loans | Middle Atlantic
Commercial mortgage loans
Gross commercial mortgage loans	214	223
Percentage of gross commercial mortgage loans	8.00%	9.00%
Commercial Mortgage Loans | Mountain
Commercial mortgage loans
Gross commercial mortgage loans	290	284
Percentage of gross commercial mortgage loans	11.00%	11.00%
Commercial Mortgage Loans | New England
Commercial mortgage loans
Gross commercial mortgage loans	143	141
Percentage of gross commercial mortgage loans	6.00%	5.00%
Commercial Mortgage Loans | Pacific
Commercial mortgage loans
Gross commercial mortgage loans	571	584
Percentage of gross commercial mortgage loans	22.00%	22.00%
Commercial Mortgage Loans | South Atlantic
Commercial mortgage loans
Gross commercial mortgage loans	660	648
Percentage of gross commercial mortgage loans	26.00%	25.00%
Commercial Mortgage Loans | West North Central
Commercial mortgage loans
Gross commercial mortgage loans	227	244
Percentage of gross commercial mortgage loans	9.00%	9.00%
Commercial Mortgage Loans | West South Central
Commercial mortgage loans
Gross commercial mortgage loans	$ 162	$ 183
Percentage of gross commercial mortgage loans	6.00%	7.00%